28 Notes on some Evidences of 



the heat of the sun is maintained by the combustion of 

 gases diffused in the medium through which it moves, and 

 which are drawn in at the polar and, after combustion, 

 returned by centrifugal force from the equatorial parts of 

 the sun into space. 



Extensive sub-aerial denudation and a warmer climate 

 succeeded the breaking up of this first period of Pliocene 

 glaciation. Another, although less severe, refrigeration took 

 place, culminating in a second glacial period, during which 

 the surface contours of the more prominent low-lying ridges 

 near Omeo were greatly abraded, and during the latter part 

 of which the heavy boulders of the Dry Gully, &c, false 

 bottoms were deposited, as well as the erratics and blocs 

 perches of the Livingstone Creek valley. This was followed 

 by a period of comparative repose, when sub-aerial denuda- 

 tion was slower and less active, a warmer and more equable 

 climate prevailing. • During this time the pipe-clays, white 

 gravelly wash, and sand-beds overlying the false bottom at 

 Dry Gully were deposited in the still icy waters of this 

 ancient mountain tarn. The fragments of fossilised wood 

 in the above deposits would also seem to prove that the 

 surrounding ranges were covered with a luxuriant timber 

 vegetation of myrtaceous genera, probably forms allied to 

 Eucalyptus Pluti. A third and final period, of glaciation 

 occurred, less extensive than either of the preceding, at the 

 breaking up of which the auriferous gravels, clays, and 

 boulders of the Livingstone Greek were deposited, and also 

 the finer gravels on the ridges near Omeo and along the 

 spurs abutting on the Livingstone Creek. The whole of 

 the present surface configuration on the undulating ranges 

 near Omeo, the Yictoria Plains, and Jim-and-Jack Creek, 

 seems to me to have been originally moulded by ice action ; 

 indeed, unless we accept the hypothesis of glacial abrasion, 

 it seems difficult to account for the rounded and flowing- 

 outlines in a rock formation which elsewhere under sub- 

 aerial influences presents surface contours bristling with 

 craggy peaks and rugged surfaces. I have elsewhere* 

 sought to explain this peculiar feature of the ranges in 

 the Livingstone Creek valley, and in the other sources of 

 the Mitta Mitta, by differences in the amount of rainfall and 

 the slower degrading influences of frosts and snows ; but on 

 viewing the orographical features in the light which the 



* Physical Features of the Australian Alps, Trans. Roy. Soc, Vict., Vol. XXI, 



